1. Field of the Invention
The present invention relates to a multi-pole connector having a plurality of contact pieces, disposed side by side, for connecting a plurality of external contact pieces of a card such as an IC memory card or a cartridge, to external contacts of a computer or the like;
2. Description of the Prior Art
There is known a multi-pole connector arranged such that the contacts of a plurality of contact pieces arranged side by side in the housing of the connector are resiliently connected to the external contact pieces disposed at the tip of a card so that the contacts are electrically conducted to the external contact pieces. A conventional multi-pole connector of this type is generally arranged such that, when a card is inserted in the connector, the contacts of the connector are raised on the external contact pieces of the card while the contact pieces of the connector are displaced against the spring loads thereof by the tip of the card.
In the conventional multi-pole connector having the arrangement above-mentioned into the connector, when pushing a card, it is required to simultaneously apply to the card both force for pushing the card and force for displacing the contact pieces of the connector against the spring loads thereof (hereinafter referred to as setting force). In the conventional multi-pole connector, the spring loads of the contact pieces of the connector may be increased to increase the resilient contact forces of the contacts and the external contact pieces, thereby to improve the reliability of contact therebetween. However, such increase in spring load results in increase in the force required for displacing the contact pieces of the connector against the spring loads thereof at the time of card setting. Thus, the card setting force is accordingly increased. The multi-pole connector has a number of contact pieces, for example 100 or more contact pieces. Accordingly, when the spring load of each of the contact pieces is increased even slightly, the spring loads of the entire contact pieces are considerably increased. This considerably increases the setting force to considerably lower the maneuverability at the time of card setting.
Accordingly, the spring loads of the contact pieces are generally determined such that the maneuverability at the time of card setting is not deteriorated so much. Thus, the conventional multi-pole connector presents the problem that the maneuverability imposes restrictions on improvements in reliability of contact between the contacts and the external contact pieces by increasing the resilient contact forces thereof.